Hydraulically retarded door closer



March 5, 1963 G. R. MILLARD ETAL HYDRAULICALLY RETARDED DooR cLosERFiled May 4, 1961 Q am Y wal ilnited gratas T@arent @t 3,079,629HYDRAUUCALLY REARDED DGR CLGSER George viiiiard, Tekonsha, and Bruce B.Bidelman and William L. Nohhs, Marshall, Mich., assignors to Ronan and Iuned, incorporated, Marshail, Mich.

Filed May 4, 1961, Ser. No. 107,776 10 Ciaiins. (Cl. 16-S2) Thisinvention relates to improvements in hydraulically retarded door closer.The principal objects of this invention are:

First, to provide an improved form of door closer of the spring actuatedhydraulically regulated cylinder type in which the retracting, doorclosing motion of a spring pressed piston is controlled through threedifferent stages or rates of travel by means of hydraulic regulatingValves actuated automatically by travel of the piston.

Second, to provide valve mechanism for a hydraulic door closer which isrelatively simple and in which the relatively small regulating parts areself cleaning s that dirt particles in the hydraulic duid will not clogthe mechanism.

Third, to provide a hydraulic door closer with an automatic safetyrelease which will relieve the hydraulic retarding pressure when apredetermined maximum pressure is created as for example, by manualclosing of the door at a faster rate than the normal closing rate of themechanism.

Fourth, to provide novel valve means in a hydraulic door closingcylinder which are easily assembled and reliable in operation in thatthere is little chance for the operating parts to get out of adjustment.

Fifth, to provide a regulatory valve system for a hydraulically retardeddoor closing pistion in which a cavity formed in the piston first movesinto cooperating engagement with a yieldable hollow valve pin to form aiirst restriction impeding the flow of iluid through the valve pin andthus creating a first retarding force on the retracting piston afterwhich the yieldable valve pin is retracted by the piston toprogressively close of a second restricted passage and thus create asecond and further retarding action on the retracting motion of thepiston; the yieldable support of the hollow valve pin furtherfunctioning as a safety release to disengage the valve pin from thechamber in the piston upon creation of excess pressure to reopen thefull dow of uid from the piston chamber.

Other objects and advantages of the invention will be apparent from aconsideration of the following description and claims. The drawings, ofwhich there is one sheet, illustrate a highly practical form of theinvention.

PEG. l is a fragmentary elevational View of a door with the door closerof the invention operatively associated therewith.

FIG. 2 is a fragmentary longitudinal cross sectional View through thecylinder and valve connections of the closer taken along the plane ofthe line 2-2 in FIG. l and illustrating the mechanism during dooropening motion of the door.

FIG. 3 is a fragmentary enlarged cross sectional view similar to FIG. 2but showing the mechanism in the fully closed position of the door.

FIG. 4 is a fragmentary transverse cross sectional view through the doorcloser cylinder and piston taken along the plane of the line 4 4 in FIG.2.

FlG. is a transverse cross sectional view through the end block of thecylinder taken along the plane of the line 5 5 in FIG. 2 andillustrating the manual adjusting valve of the closer.

FiG. l illustrates the relationship of the door closer of the inventionto the door which it is arranged to control. As shown in FlG. l aswinging door 1 is mounted in a doorway 2 with the door closing cylinder3 of the invention mounted in the space which already exists in theusual header of the door frame. The cylinder 3 is provided with areciprocaole piston rod 4 which is actuated by a suitable cam or crankmechanism indicated generally at 5 to withdraw or advance the piston rodfrom the cylinder when the door is opened and to control the retractionof the piston rod into the cylinder under spring pressure as will bedescribed to regulate the closing motion of the door. The cam or crankmechanism 5 has a drive pin 6 which is connected to the door to couplethe door to the closer mechanism. Details ofthe crank or cam mechanism 5are not disclosed as a variety of door closing cams and cranks are wellknown in the prior art and can be utilized in combination with thepiston rod 4.

As appears more clearly in FIGS. 2 to 5, the door closer cylinder 3 isprovided with a rear end block 7 and a front end block 8 considering thefront of the cylinder as the end from which the piston rod 4 extends.One of the end blocks, in this case the front end block 3, is providedwith mounting anges 9 for securing the cylinder to a suitable supportlocated in the space within the header of the door frame. The piston rod4 carries a piston l1 at its inner end and both the piston and thepiston rod are urged inwardly of the cylinder by a relatively heavy doorclosing spring l2 engaged with the abutment ring i3 on the piston rodand the inner side of the front end block 8. Upon inward retractingmotion of the piston and piston rod toward the left as viewed in FIG. 2,hydraulic duid hereafter referred to as oil, is displaced by the piston'l1 through the hollow valve pin 14 to passages in the rear end block 7from which the oil is delivered past a manually adjustable metering pin15 to the passage i6 and return pipe 17. The pipe 17 connects with thefront block S and passages 18 therein to return the oil to the oppositeor front side of the piston.

Considering in greater detail the construction of the piston 11 and itsmounting on the piston rod 4, it will be noted that the piston has acylindrical body with a groove therearound for the seal ring i9. Thecenter of the piston ii defines a bore slidably receiving the reducedinner end portion 29 of the piston rod 4. A pin 2l passed diametricallythrough the piston is loosely received in an oversized bore 22 in thepiston rod permitting the piston to shift axially along the piston rod.The side of the reduced portion 29 of the piston rod is attened or cutaway as at 23 (see FIG. 4) forming a passage completely along the sideof the reduced portion and through the piston so that when the pistonrod moves outwardly to the right as shown in FIG. 2, the outer face ofthe piston il moves relatively inwardly away from the shoulder 24 on thepiston rod exposing the outer end of the flattened area 23 and oil canbe displaced from the right hand end of the cylinder 3 along the lat 23to the left hand side of the piston. Upon inward motion of the pistonrod the resistance of the oil against the inner face of the piston movesthe piston against the shoulder 2d and prevents return ilow of oilthrough the center of the piston. The piston and piston rod thus form aone way check valve for introducing oil to the left side of thecylinder.

On its right side the piston 11 carries a cylindrical liange 25 to whichis secured a short cylindrical wire screen 26 with a bushing 27 on itsouter end which slides on the piston rod 4. The inner end of the pistonrod 4 projects through the piston 11 and has a short bore or recess 28formed therein coaxially with the valve pin 14. The recess 23 cooperateswith the regulating valve 14 as will be described is greater detail.

Considering the rear end member 7 and the regulating valve 14 in greaterdetail, it will be noted that the end member defines a central bore orchamber 29 which communicates at its rear end with the bore 3@ and inturn with the stepped lateral bore 31 within which the manuallyadjustable needle valve is mounted. The outer or right end of the endmember 7 defines a counterbore 32 around the end of the chamber 29 and avery line inclined notch 33 is cut in the shoulder between the bore 29and the counter bore 32. The hollow tubular needle valve 14 has anenlarged shoulder 34 which lits slidably .and sealingly in the chamberor bore29 with -a spring 35 bearing against the inner end of the needlevalve and Apressing the shoulder axially outwardly against a retainingring 35 pressed into the counter bore 32. The outer elongated end of theneedle valve is passed guidingly but in nonsealing relation through theretaining ring 36.

The outwardly projecting right end of the tubular needle valve 14 istapered as at 37 so as to have a selfcentering engagement with the`recess 2S in the piston rod and the tapered end of the needle valve isprovided with a small calibrated notch 38 forming a small controlledopening into the chamber 2S and the outer end of the needle valve whenthe inner end of the piston rod Y isV pressed inwardly over the outerend of the needle valve as shown in FIG. 3. j

From the foregoing description of the structure of the cylinder andvalve mechanisms vit will be apparent that when the piston rod andpiston .have moved fully to the .rightras viewed in FIG. 2 most of theoil is displaced into the left end of thecylinder. ln being so displacedthe oil passes through the screen 26 before it reaches the passage alongthe hat 23 on the piston rod where the rod passes through the piston.Subsequent inward retracting motion of the piston rod caused byexpansion of the spring 12 and closing motion of the door will rstdisplace oil freely from the left end of the lcylinder through theexposed open end of the hollow needle'valve 14, chamber 29, passages 30and 31 andl past the adjusting valve 15 tothe return tube 17 from wherethe oil reenters the right side of the cylinder. The initialdisplacement is relatively unobstructed and is Vcontrolled primarily bythe adjusting valve 15. Initial closing motion of the door vby thespring 12 and piston rod 4 is'accordingly relatively rapid. As thepiston 1'1 approaches the hollow needle valve 14 `the tapered end of theValve enters the recess 28 so that any continued displacement of oilmust be through the metering notch 38 in the end of the needle valve and,through the small metering notch 33 at the outer end of nthe valvechamber 29vin the end member 7 The combined oil vtlow through these twometered passages constitutes a iirst reduced ilow to impose a firstdegree of restriction to .further inward motion for the piston 11. Asthe piston lcontinues inwardly at the rst reduced rate of travel, thehollow needle valve Ais pressed rearwardly or inwardly by engagementwith the piston rod around the recess 28 so that .the enlarged portion34 around the needle valve moves inwardly beyond the notch 33 as isshown in FIG. 3 thus cutting olf the flow through the notch 33 andcreating a second reduction and a second degree of increased resistanceto inward motion of the piston. All oil dis- .placed by final inwardmotion of the piston rod and piston Ymust flow through the irst reducedpassage 38 and through the hollow tubular needle valve to the returnpipe 17. The vfinal closing motion of the door is thus slowed to aminimum to prevent objectionable slamming.

Should the pressure created in the left end of the cylin- "der 3 byinward movement 'of the piston 11 be raised substantially above thenormal pressure created by the spring 12, -this increased pressure actsagainst the Youter -face of the enlarged portion 34 of the needle valveand compresses the needle valve against the pressure of spring 29 toretract the needle valve further than the recess or cavity 2,8 thusreopening the outer end of the tubular needle valve to the left end ofthe cylinder 3. This reopening ofthe needle valve reduces the'resistanceto inward motion `of .the piston permitting .relief of excess pressurethrough the needlevalve Vand in addition permitting more rapid inwardmotion of the piston rod and piston.

4 The hollow needle valve 14 with its enlarged portion 34 and the spring29 thus constitute a safety relief valve cooperating with the pistonY 11to permit more rapid closing of the door 2. The safety valve arrangementwill Y become operative, for example, should a person push the doorclosed at a faster rate than the normal closing rate of the .returnspring 12. The safety valve prevents the building up of excess pressuresin the left end of the cylinder 3 which might damage other parts of thesystem and also permits the door to be closed manually at a faster ratethan by the closing spring without forcing the door against the normalrestraining pressure in the left end of the cylinder. lt is a feature ofthe'valve system that the two primary restricted passages formed by thenotches -33 and 3S are opened regularly by each operai'ton of the doorand are thus self cleaning as oil is forced over the notches. It,therefore, ris practically impossible for the metering passages tobecome clogged and inoperative.

-What is claimed as new is:

l. Door closer mechanism including in combination a cylinder'havinginner and outer end members with a piston rod projecting through the.outer end member,

an oil return pipe extending between Asaid end members and communicating'through return passages in the end members with opposite ends of saidcylinder,

a manually adjustable regulating valve in one of said passages,

a piston in said cylinder connected to said rod for reciprocation by therod,

a spring 'biasing said rod inwardly into said cylinder,

means providing a limited sliding engagement between said `piston andsaid rod, and a passage formed by a ilattened area on therod uncoveredby inward displacement of the piston relative to the rod forming aninwardly opening and outwardly closing check valve through said piston,

a bore formed in the inner endmember as part of the return passagetherethrough,

a hollow needle Valve having an enlarged portion slidably and sealinglyreceived in said bore,

a second spring biasing said needle valve outwardly of said bore,

a groove in the wallrat the outer end of said bore forming a firstrestricted passage past said enlargedportion of said needle valve intheoutwardly projected position of the needle valve,

a recess formed in the inner end of said rod positioned vto receive andsubstantially close the hollow outer end of the needle valve in aninwardly retracted position of said rod,

the end .of said needle valve being tapered to enter into said recessand having a small groove in the tapered surface of the valvecooperating with the Wall of the recess to form a secondrestrictedpassage to the 'end of the hollow needle valve when said piston isretracted over .said needle valve.

2. Door closer mechanism including in combination a cylinder Yhavinginner and outer end members with a pis- Vton rod projecting through theouter end member,

an 'oil return pipe extending between said endmembers and communicatingthrough return passages in the end members with opposite ends of saidcylinder,

a piston in said cylinder connected to said rod for vre-Y ciprocation bythe rod, l a spring biasing said rod inwardly intosaid cylinder, meansproviding a limited'sliding engagement between said piston and said rod,and apassage uncovered byV inward displacement of the piston relativeYto the rod vforming an inwardly opening and outwardly closing checkvalve through saidpiston,

a boreV formed in the inner end member as'part of the return passagetherethrough,

a hollowneedle valve having an enlarged portion slid- Aablyfandsealingly .received in j'said bore,

a second spring biasing said needle valve outwardly of said bore,

means forming a rst restricted passage past said enlarged portion ofsaid needle valve in the outwardly projected position of the needlevalve,

a recess formed in the inner end of said rod positioned to receive andsubstantially close the hollow outer end of the needle valve in aninwardly retracted position of said rod,

the end of said needle valve having a small groove in the taperedsurface of the valve cooperating with the wall or" the recess to form asecond restricted passageV to the end of the hollow needle valve whensaid piston is retracted over said needle valve.

3. Door closer mechanism including in combination a cylinder havinginner and outer end members with a piston rod projecting through theouter end member,

a liuid return pipe extending between the inner one of said end membersand the other end of said cylinder and communicating through a returnpassage in said one end member with opposite ends of said cylinder,

a manually adjustable regulating valve in said passage, a piston in saidcylinder connected to said rod for reciprocation by the rod,

a spring biasing said rod inwardly into said cylinder, means providing alimited sliding engagement between said piston and said rod, and apassage uncovered by inward displacement of the piston relative Ato therod forming an inwardly opening and outwardly closing check valvethrough said piston,

a bore formed in the inner end member as part of the return passagetherethrough,

a hollow needle valve having an enlarged portion slidably and sealinglyreceived in said bore,

a second spring biasing said needle valve outwardly of said bore, l

a groove in the wall at the outer end of said bore forming a firstrestricted passage past said enlarged portion of said needle valve inthe outwardy projected position-of the needle valve,

a recess formed in the inner end of said rod positioned to'receive andsubstantially close the hollow outer end of the needle valve in aninwardly retracted position of said rod,

the end of said needle valve being adapted to enter into said recess andcooperating with the wall of the recess to form a second restrictedpassage to the end of the hollow needle valve when said piston isretracted over said nee le valve.

4. Door closer mechanism including in combination a cylinder' havinginner and outer end members with a piston rod projecting through theouter end member,

a fluid return pipe extending between the inner one of said end membersand the other end of said cylinder and communicating through a returnpassage in said one end member with opposite ends of said cylinder,

a piston in said cylinder connected to said rod for reciprocation by therod,

a spring biasing said rod inwardly into said cylinder,

means forming an inwardly opening and outwardly closing check valvethrough said piston,

a bore formed in the inner end member as part of the return passagetherethrough,

a hollow needle valve having an enlarged portion slidably and sealinglyreceived in said bore,

a second spring biasing said needle valve outwardly of said bore,

a groove in the Wall at the outer end of said bore forming a firstrestricted passage past said enlarged portion of said needle valve inthe outwardly projected position of the needle valve,

the inner end or" said rod being adapted to substantially close thehollow outer end of the needle valve in an inwardly retracted positionof said rod,

the end of said needle valve being cooperative with the end of said rodto form a second restricted passage to the end of the hollow needlevalve when said piston is retracted against said needle valve.

5. Door closer mechanism including in combination a cylinder havinginner and outer end members with a piston rod projecting through theouter end member,

a uid return pipe extending between the inner one of said end membersand the other end of said cylinder and communicating through a returnpassage in said one end member with opposite ends of said cylinder,

ya piston in said cylinder connected to said rod for reciprocatiou bythe rod,

a spring biasing said rod inwardly into said cylinder,

means forming an inwardly opening and outwardly closing check valvethrough said piston,

a bore formed in the inner end member as part of the return passagetherethrough,

a hollow needle valve having an enlarged portion slidably and sealinglyreceived in said bore,

a second spring biasing said needle valve outwardly of said bore,

the inner end of said rod being adapted to abut and 'substantially closethe hollow outer end of the needle valve in an inwardly retractedposition of said rod,

the end of said needle valve being cooperative with the end of said rodto form a restricted passage to the end of the hollow needle valve whensaid piston is retracted against said needle valve.

6. Door closer mechanism including in combination a cylinder havinginner and outer end members with a piston rod projecting through theouter end member,

a tiuid return pipe extending between the inner one of said end membersand the other end of said cylinder and communicating through a returnpassage in said one end member with opposite ends of said cylinder,

a piston in said cylinder connected to said rod for reciprocation by therod, i

a spring biasing said rod inwardly into said cylinder,

means forming an inwardly opening and outwardly closing check valvethrough said piston,

a bore formed in the inner end member as part of the return passagetherethrough,

a hollow needle valve slidably and sealingly received in said bore, v

a second spring biasing said needle valve outwardly of said bore,

the inner end of said rod being adapted to abut and substantially closethe hollow outer end of the needle valve in an inwardly retractedposition of said rod,

the end of said needle valve being cooperative with the end of said rodto form a restricted passage to the end of the hollow needle valve whensaid piston is retracted against said needle valve.

'7. Door closer mechanism including in combination a cylinder havinginner and outer end members With a piston rod projecting through theouter end member,

a huid return pipe communicating through a return passage in the innerone of said end members with opposite ends of said cylinder,

a piston in said cylinder connected to said rod for reciprocation by therod,

a spring biasing said rod inwardly into said cylinder,

means providing a limited sliding engagement between said piston andsaid rod, and a passage uncovered by inward displacement of the pistonrelative to the rod forming an inwardly opening and outwardly closingcheck valve through said piston,

a bore formed in the inner end member as part of the return passagetherethrough,

a hollow needle valve having an enlarged portion slidably and sealinglyreceived in said bore,

a second spring biasing said needle valve outwardly of said bore,

and means forming a restricted passage past said envlargedportion of'said needle valve in the outwardly projected position of the needlevalve,

`a recess formed in the inner end of said rod positioned to receive Vandsubstantially close the hollow outer end of the needle valve in aninwardly retracted position of said rod.

S. .Door closer mechanism including in combination 'a cylinder .havinginner and outer end members with a piston -rod projecting through -theouter end member,

a uid return pipe communicating through a return passage .in Ithe innerone of said vend members with opposite ends of said cylinder,

a piston in said cylinder connected to said rod for reciprocation byYthe rod,

a spring biasing said `rod inwardly into said cylinder, means forming aninwardly opening and outwardly :closing check valve through .saidpiston,

a bore formed in lthe inner end member as part of ythe return vpassagetherethrough,

a hollow needle valve having an enlarged portion slidably and sealinglyreceived .in said bore,

a second spring biasing said needle valve outwardly of said bore,

and means forming va restricted passage past said enlarged portion ofsaid needle valve in .the outward- Y yly projected position `of the'needle valve,

said .rod being arranged .to substantially close the -hollow outer 'endof the needle valve inan inwardly retracted position of said rod.

'9. Door closer vmechanism including in combination `aE-,cylinder havinginner and -outer end members :with a piston rod projecting through vtheouter end member,

a fluid return pipe forming a return passage extending betweenr theinner one of said end members and the opposite end of said cylinder,

a piston in said cylinder connected to said rod for reciprocation bytherod,

a spring biasing said rod` and piston inwardly into 'said cylinder,

means forming Aan inwardly opening and outwardly closing check valvethrough said piston,

a Vbore formedin the Vinner end member as part of the return passagetherethrough,

'a hollow needle-valve slidably and sealingly received in said bore,

a second spring biasing said needle valve outwardly of said bore,

said rod being arranged Ito substantially close the hollow outer end ofthe needle valve in an inwardly retracted position of said rod.

l0. In a hydraulically retarded door closer having a a cylinder memberand a Vpiston member reciprocable therein and spring biased to aretracted position,

said members being adapted to be connected between a Ifixed point and adoor to'reciprocalte relative to each other with movement of the door,

.means including a one way check valve forming a iirst passage between.the opposite ends of said cylinder and through 'said piston member,

means forming a second passage between lthe opposite ends of saidcylinder and including a bore formed in one end of said cylinder and aconduit communi- `eating with the bore and the other end of saidcylinder,

means forvarying the effective size of said second passage including avhollow tubular needle valve axially slidably mounted in one of saidmembers and engageable with the other of said members near the end .ofIthe retracting motion of the members,

said other of said members; having .a seat Vformed thereon engaged bysaid valve and coacting therewith to form a'substantial 'closure on saidseat with 'a small metered opening therebetween .between the Vinteriorof said'cylinder and vsaid second passage lthrough .said .hollow .needlevalve,

and a spring acting between said valve and said one of said 4membersurging .said valve toward said other 0f said members,

said valve'and saidone member in which it is mounted dening asecondmetered opening from said cylinder to said second passage which is openin the extended position of the valve and closed when said valve ispushed in against said spring.

References Cited ,in the le of this patent UNITED `STATES PATENTS12,735,132. Wartian Feb. 21, 1956

5. DOOR CLOSER MECHANISM INCLUDING IN COMBINATION A CYLINDER HAVINGINNER AND OUTER END MEMBERS WITH A PISTON ROD PROJECTING THROUGH THEOUTER END MEMBER, A FLUID RETURN PIPE EXTENDING BETWEEN THE INNER ONE OFSAID END MEMBERS AND THE OTHER END OF SAID CYLINDER AND COMMUNICATINGTHROUGH A RETURN PASSAGE IN SAID ONE END MEMBER WITH OPPOSITE ENDS OFSAID CYLINDER, A PISTON IN SAID CYLINDER CONNECTED TO SAID ROD FORRECIPROCATION BY THE ROD, A SPRING BIASING SAID ROD INWARDLY INTO SAIDCYLINDER, MEANS FORMING AN INWARDLY OPENING AND OUTWARDLY CLOSING CHECKVALVE THROUGH SAID PISTON, A BORE FORMED IN THE INNER END MEMBER AS PARTOF THE RETURN PASSAGE THERETHROUGH, A HOLLOW NEEDLE VALVE HAVING ANENLARGED PORTION SLIDABLY AND SEALINGLY RECEIVED IN SAID BORE, A SECONDSPRING BIASING SAID NEEDLE VALVE OUTWARDLY OF SAID BORE, THE INNER ENDOF SAID ROD BEING ADAPTED TO ABUT AND SUBSTANTIALLY CLOSE THE HOLLOWOUTER END OF THE NEEDLE VALVE IN AN INWARDLY RETRACTED POSITION OF SAIDROD, THE END OF SAID NEEDLE VALVE BEING COOPERATIVE WITH THE END OF SAIDROD TO FORM A RESTRICTED PASSAGE TO THE END OF THE HOLLOW NEEDLE VALVEWHEN SAID PISTON IS RETRACTED AGAINST SAID NEEDLE VALVE.